Plastic relay structure and method of making



April 7, 1964 FULLER 3,128,355

PLASTIC RELAY STRUCTURE AND METHOD OF MAKING Filed Oct. 19, 1959 I IImvll. vlim'llz III I INVENTOR -E EVANDER K FULLER ATTORNEY United StatesPatent 3,128,355 PLASTIC RELAY STRUQTURE AND METHGD 9F MAKING Evander K.Fuller, Greenshoro, N.C., assignor to Western Electric Company,Incorporated, New York, N.Y., a corporation of New York Filed Oct. 19,195?, Ser. No. 847,247 9 Claims. (Cl. 260-87) This invention relates toan electromagnetic relay and a method of making the relay. Moreparticularly this invention relates to an electromagnetic relay havingan integral resilient insulating support and armature and a method offorming the support and armature.

An object of the present invention is to provide a new and improvedelectromagnetic relay and a method of making the relay.

Another object is the provision of an electromagnetic relay having anintegral resilient insulating support, and a method of forming thesupport.

A method of making a relay from an integral sheet of resilientinsulating material illustrating certain aspects of the invention mayinclude the steps of fixing contacts and an armature to the sheet anddeforming the sheet to align the contacts in space opposition. A coil issecured on the sheet adjacent the armature whereby attraction of thearmature by the coil flexes the resilient sheet to operate the contacts.

A relay illustrating certain aspects of this invention may include asupport formed of an integral sheet of resilient insulating material,contacts fixed to the resilient support in space opposition, and anarmature positioned within the support responsive to the energization ofa relay coil flexing the resilient support to operate the contacts.

A complete understanding of the invention may be had from the followingdetailed description of several embodiments thereof when read inconjunction with the appended drawings, in which:

FIG. 1 is a side sectional view of a relay embodying the principles ofthe invention;

FIG; 2 is a perspective view of a preformed sheet of resilientinsulating material to be formed into the shape of the relay supportshown in section in FIG. 1;

FIG. 3 is a side sectional view of a make-break contact type relayexemplifying another embodiment of the invention;

FIG. 4 is a front sectional view of the relay taken along the line 44 ofFIG. 3; and

FIG. 5 is a perspective view of a preformed sheet of resilientinsulating material to be formed into the shape of the relay supportshown in FIGS. 3 and 4.

Referring now to the drawing, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in FIG. 1 a relay, generally designated by the numeral11, having an integral resilient insulating support 12 of a materialsuch as the plastic, sold under the trade name Plexiglas. The desiredconfiguration may be formed by any well known technique, such asmolding, stamping, cutting, or the like. Securely embedded within orfixed to the support 12 is an armature 13 of a paramagnetic material ofhigh permeability, such as soft iron. Contacts 14 having terminal leads15 are fixed to the support 12 to form a switch gap 16, the contacts 14being disengaged to maintain the switch gap 16 open when the relay 11 isnot operated.

A relay-operating coil 17 having leads 18 is positioned fixedly within arecess 19 which is formed within the support 12. The coil 17 ispositioned such that its core 21 is in space opposition with thearmature 13 to form an air gap 22 when the relay 11 is in an unoperatedcondition. The relay 11, as shown in FIG. 1, is of the ice type referredto as normally open; i.e., the relay contacts 7 14 are disengagedforming the switch gap 16 when there is no electrical current applied tothe leads 18 of the coil 17.

In operation when an electrical current is applied by leads 18 to thecoil 17, it creates a strong magnetic field causing the armature 13 tobe attracted to and held in engagement with the core 21. Such attractioncauses the resilient support 12 to flex or to temporarily distort so asto bring contacts 14 into mutual engagement with a predeterminedpressure. This pressure is primarily dependent upon the width of theswitch gap 16 with respect to that of the air gap 22, which may beslightly wider, and the flexibility or elasticity of the support 12.Hence, when the coil 17 is energized, a circuit, not shown, connected byleads 15 to the contacts 14, is closed, and upon the removal ofelectrical current from the coil 17, the contacts 14 disengage to openthe circuit, not shown, connected to them.

In making the relay 11 of FIG. 1, the armature 13 and contacts 14 arefixed to a preformed integral sheet of resilient insulating material byany of the conventional methods of joining metal and resilient material,such as heating and embedding, plastic deformation, utilization offasteners, gluing, cementing, or the like. If the heating-and-embeddingjoining method is used, it may be desirable, for example, to firstremove some of the material of the support 12 before embedding theheated armature 13. After the armature 13 and contacts 14 are so fixed,the sheet is deformed to align the contacts 14 in space opposition. Suchdeformation may be achieved simply by bending or folding the sheet pastits elastic limit. It may be desirable, depending on the physical andchemical characteristics of the sheet, to heat the sheet at locationswhere the bending is to be performed to aid in the bending operation.Such heating, for example, may be concentrated along lines 23, FIG. 2,and while the sheet is in a heated condition, it may be bent along lines23 to form the support 12.

A second embodiment of the relay is shown in FIGS. 3, 4, and 5. Themethods of making the second embodiment are somewhat similar to themethods of making the first embodiment. A sheet of resilient insulatingmaterial is fabricated into the configuration of a T, FIG. 5 having astem, an upper crossbar, and a lower crossbar. Both the upper and thelower crossbars have two portions of unequal length extending laterallyat right angles from the stem. Also, the upper crossbar is parallel toand spaced from the lower crossbar. Contacts 24 are positioned withinthe upper edge of the upper crossbar and in the base of the T of thesheet as shown in FIG. 5. Armature 13 is fixed to the stem intermediatethe lower crossbar and the base. Apertures 26 are then formed throughthe lower crossbar at each side of the stem.

As shown in FIG. 5, the spacing of folding lines 23 of the uppercrossbar is unequal so that when it is folded into the shape of FIGS. 3and 4, the contacts 24 of the upper crossbar are vertically aligned inspace opposition. Also, the spacing of the folding lines 23 of the lowercrossbar is unequal so that when it is folded into the shape shown inFIGS. 3 and 4, the apertures 26 are spaced in vertical alignment abovethe stem.

An operating coil 17 is secured within the vertically aligned apertures26 of the folded lower crossbar by gluing, cementing, or the like. Next,the portion of the stem extending below the lower crossbar is folded toplace the armature 13 in vertical space alignment above the coil 17 andto place the contact 24 fixed to the base of the T in sandwichedrelationship between the vertically aligned contacts 24 of the uppercrossbar such that attraction of the armature 13 by the coil 17 causesthe contact 24 of 3 the stem to move from one of the vertically alignedcontacts 24 to the other.

The second embodiment, FIGS. 3 and 4, differs in structure from thatshown in FIG. 1 in that three cooperating contacts 24 are secured tosupport 25 instead of the two cooperating contacts 14 of the embodimentof FIG. 1. Hence, the second embodiment constitutes a make-break relay.Also, the support 25 is provided with apertures 26 for fixedly locatingthe coil 17.

As another embodiment of the relay shown in FIGS. 3, 4, and 5, one ofthe portions of the upper crossbars of the resilient sheet could beomitted. The sheet would be fabricated into the configuration of an Lhaving a stern and an upper crossbar extending laterally from one edgeof the stern and a lower crossbar extending laterally from both edges ofthe stem. Contacts 24 and an armature 13 would be fixed in the same orsimilar manner as in the second embodiment. Also, the folding would beaccomplished in the same or similar manner to form a relay similar tothat shown in FIGS. 3 and 4, except that there would be only twocooperating contacts (instead of three cooperating contacts) that is,either normally open or normally closed, depending upon which portion ofthe crossbar of the second embodiment was omitted.

It should be understood that the above-described embodiments and methodsare merely illustrative and that numerous modifications may be madewithin the spirit and scope of the invention. Further, the particularrelays and methods of making them are not limited solely to theabove-described embodiments and methods.

What is claimed is:

l. A method of making a relay from an integral sheet of resilientelectrically insulating material comprising the steps of heating a pairof electrical contacts and an armature, fixing by plastic deformationthe heated contacts and armature to the sheet, deforming the sheet toalign the contacts in space opposition, and supporting a coil on thesheet sufficiently near the armature that energizing the coil attractsthe armature and flexes the resilient sheet to operate the contacts.

2. A method of making a relay comprising the steps of fabricating asheet of resilient electrically insulating material into theconfiguration of a T having a stem and an upper and a lower crossbar,positioning electrical contacts in the upper crossbar of the T-shapedsheet, fixing another electrical contact to the base of the stem of theT, fixing an armature to the stem intermediate the lower crossbar andthe base of the stem, forming apertures through the lower crossbar ateach side of the stern, folding the upper crossbar to align the contactsthereon in vertical space opposition, folding the lower crossbar at thejuncture of each side of the lower crossbar with the stem to space theapertures in vertical alignment above the stem, securing a coil withinthe vertically aligned apertures of the lower crossbar, and then foldingthe portion of the stem extending below the lower crossbar to place thearmature in vertical space alignment above the coil and to place thecontact fixed to the base of the T in sandwiched relationship betweenthe vertically aligned contacts of the upper crossbar such thatattraction of the armature by the coil causes the contact on the stem tomove from one of the vertically aligned contacts to the other.

3. A method of making a relay comprising the steps of fabricating asheet of resilient electrically insulating material into theconfiguration of an L having a stem and an upper crossbar extendinglaterally from one edge of the stem and a lower crossbar extendinglaterally from opposite edges of the stem, the upper crossbar beingparallel to and spaced from the lower crossbar, positioning anelectrical contact on the upper crossbar of the L-shaped sheet, foldingthe upper crossbar to align the contact in vertical spaced relationshipto the stem, fixing another electrical contact to the base of the stemof the L, fixing an armature to the stem intermediate the lower crossbarand the base of the stem, forming apertures through the lower crossbarat each side of the stem, folding the lower crossbar at the juncture ofeach side of the lower crossbar with the stem to space the apertures invertical alignment above the stem, securing a coil within the verticallyaligned apertures of the lower crossbar, and then folding the portion ofthe stern extending below the lower crossbar to place the armature invertical space alignment above the coil and to place the contact fixedto the base of the L in opposition with contact of the upper crossbarsuch that attraction of the armature by the coil causes the contact ofthe stem to operate.

4. A relay structure comprising a strip of resilient, insulatingmaterial formed in a loop with the ends thereof spaced from each other,a pair of contacts attached to said ends to form a switch gap, anarmature secured to the inside of the strip, and a coil secured to theinside of the strip and spaced from said armature for attracting thearmature to flex the resilient loop and move the contacts through theswitch gap and into engagement with each other.

5. A relay comprising an operating coil having a magnetizable core, anintegral resilient electrically insulating support made from a strip ofmaterial formed into substantially a rectangle having a gap formed inone side by the ends of the strip, the ends of said strip havingcooperating metal contacts fixed thereto so as to form a switch gap, anoperating coil fixed within the support, an armature fixed within thesupport opposite the magnetizable core to form an air gap between thecore and the armature, said air gap having a width slightly larger thanthe width of the switch gap so that upon operation of the relay, thecontacts thereof will close with a predetermined pressure.

6. A relay which comprises a support of a block-C configuration, theopen part of the block 0 forming a gap, said block-C configurationhaving an inner surface and an outer surface and composed of resilientelectrically insulating material, electrical contacts fixed to thesupport adjacent the gap of the block-0, an armature fixed to thesupport inner surface at the top of the block-C configuration, and anoperating coil fixed to the inner surface of the support at the bottomof the block-C configuration in operating spaced relation with thearmature.

7. A relay comprising an integral resilient electrically insulatingsupport having an inner surface and an outer surface and a bottom with arecess formed in the inner surface thereof, a first side folded upwardlyfrom the bottom, a top folded from the first side parallel and equal insize to the bottom, and a second side formed by folding a portion of thetop downwardly and a portion of the bottom upwardly to form a gap, thesecond side being parallel and equal in size to the first side; a pairof cooperating, normally open electrical contacts fixed respectively tothe outer ends of the gap to form a switch gap; an operating coil havinga magnetizable core secured within the recess of the bottom; and anarmature fixed to the inner surface of the top directly over theoperating coil to form an air gap between the core and the armature sothat upon energization of the relay the armature will be attracted toand held by the core, thereby closing the relay contacts.

8. A relay comprising an integral resilient electrically insulatingsupport having an inner surface and an outer surface and a bottom with arecess formed in the inner surface thereof, a first side folded upwardlyfrom the all...

fixed to the inner surface of the top in spaced alignment with theoperating coil to form an air gap between the core and the armature,said air gap having a width slightly larger than the Width of the switchgap so that upon the energization of the relay the contacts thereof willclose with a predetermined pressure.

9. A relay comprising an integral resilient electrically insulatingsupport having an inner surface and an outer surface and a bottom, aside folded upwardly from the bottom, a top folded from the sideparallel and equal in size to the bottom, a pair of apertured tabsextending laterally at right angles from the bottom, the tabs beingadjacent the side and the apertures being aligned along an axisperpendicular to the bottom; an operating coil having a magnetizablecore, the coil being fixed in the apertures so that the base of the coilis supported by the bottom; an armature fixed to the top in alignedspaced opposition with the core; a first electrical contact fixed to theouter end of the top; a pair of laterally extending projections spacedfrom and parallel to the tabs; and a second and a third electricalcontact fixed to the projections such that said contacts are axiallyaligned in space opposition, the first contact being sandwiched betweensaid contacts whereby attraction of the armature by the core of the coilcauses the first contact to move from the second to the third contact.

References Cited in the file of this patent UNITED STATES PATENTS1,664,212 Hawkinson Mar. 27, 1928 2,174,355 Sundstrom Sept. 26, 19392,377,604 Belden June 5, 1945 2,529,212 Coulter Nov. 7, 1950 2,549,323McMullen Apr. 17, 1951 2,576,856 Robertson Nov. 27, 1951 2,587,568Eisler Feb. 26, 1952 2,632,071 Rinke Mar. 17, 1953 2,856,674 Hill Oct.21, 1958 2,877,324 Oshry Mar. 10, 1959 2,878,348 Haydon et al Mar. 17,1959 2,880,378 Lindseth Mar. 31, 1959 2,884,574 Jaidinger Apr. 28, 19592,916,580 Seele Dec. 8, 1959 2,918,547 Titus Dec. 22, 1959 2,943,167Hughes et a1 June 28, 1960

4. A RELAY STRUCTURE COMPRISING A STRIP OF RESILIENT, INSULATINGMATERIAL FORMED IN A LOOP WITH THE ENDS THEREOF SPACED FROM EACH OTHER,A PAIR OF CONTACTS ATTACHED TO SAID ENDS TO FORM A SWITCH GAP, ANARMATURE SECURED TO THE INSIDE OF THE STRIP, AND A COIL SECURED TO THEINSIDE OF THE STRIP AND SPACED FROM SAID ARMATURE FOR ATTRACTING THEARMATURE TO FLEX THE RESILIENT LOOP AND MOVE THE CONTACTS THROUGH THESWITCH GAP AND INTO ENGAGEMENT WITH EACH OTHER.